Surface applications such as bridge deck covering, pavement patching, roofing applications and other coverings

ABSTRACT

A nonheat-sealed polypropylene fabric, e.g., nonheat-sealed nonwoven polypropylene mat or fabric, is used within an asphalt aggregate surface covering. A cutback asphalt or asphalt emulsion is spread, a mat of nonheat-sealed polypropylene fabric is laid into the asphalt, further adhesive can be applied together with aggregate and finally, the mass is smoothed by rolling to make the final surface application covering. Blisters which are formed when using heat-sealed fabric are avoided.

United States Patent Appl. No. Filed Patented Assignee SURFACE APPLICATIONS SUCH AS BRIDGE DECK COVERING, PAVEMENT PATCI-IING, ROOFING APPLICATIONS AND OTHER COVERINGS 4 Claims, No Drawings [1.8. CI 94/9, 94/23, 94/3 Int. Cl E0lc 7/18 Field of Search 94/3, 4, 9, 7, 23

References Cited UNITED STATES PATENTS 2/1928 Wenrich 94/3 X 1,854,512 4/1932 Heppes 94/3 UX 1,893,742 1/1933 Heidman 94/3 FOREIGN PATENTS 1,015,746 1/1966 Great Britain 94/4 Primary Examiner.lac0b L. Nackenolf An0rney Young and Quigg ABSTRACT: A nonheat-sealed polypropylene fabric, e.g.,

SURFACE APPLICATIONS SUCH AS BRIDGE DECK COVERING, PAVEMENT PATCHING, ROOFING APPLICATIONS AND OTHER COVERINGS In one of its aspects this invention relates to the preparation of a fabric-containing surface covering or patching. In another of its aspects the invention relates to an adhesive-fabric combination application to surfaces. In a further aspect of the invention it relates to the use of nonheat-sealed polypropylene l fabric or mat for hard surface application.

In one of its concepts the invention provides a method for covering a surface as herein described which comprises applying to a preferably clean surface an adhesive coating, for example, a cutback asphalt or asphalt emulsion which preferably will be of a cationic type, laying a mat of nonheat-sealed polypropylene fabric into the coating, applying further adhesive as may be desired, together with aggregate, and finally, smoothing the mass as by rolling or otherwise to make the final surface application covering.

We have found that when using heat-sealed and sometimes woven polypropylene fabric blisters can occur. It is now through that the hot rolling process produces certain stresses in the fabric which later relax and cause humps or blisters on the surface of the roof or road which has been covered therewith. lndeed, even cold asphalt, when applied to the heat-sealed nonwoven fabric made of polypropylene, seems to cause a relaxation of the heat-sealed surfaces, e.g., some expansion, and buckling or blistering occurs.

We have found that replacing the polypropylene fabric which has been heat-sealed with nonheat-sealed polypropylene fabric or mat that blisters do not appear when such a mat is placed on a hard surface with asphalt sealant. The finished surface or patches made with the nonheattreated fabric is different from those made with the normal, i.e., heat-treated fabric. The raised nap surface of the nonheat-sealed fabric holds more asphalt sealant without running. An improved imbedment of aggregate is obtained.

It is an object of this invention to prepare a surface covering. it is another object of this invention to obtain a better surface covering. It is a further object of this invention to obtain improved imbedment of aggregate in an adhesive-containing surface covering also containing aggregate. It is a still further object of this invention to suitably use a nonwoven polypropylene fabric or mat which has not been heat-sealed or surface treated in any way.

Other aspects, concepts and the several advantages of this invention are apparent from a study of this disclosure and the appended claims.

According to the present invention nonheat-sealed polypropylene fabric or mat is used together with adhesive and with aggregate and then smoothed or rolled or otherwise compacted as may be desired.

The following data have been obtained using nonwoven heat-sealed" and nonheat-sealed polypropylene fabric These pieces should weigh the same, but these two 6" 6" samples were from different production runs, but essentially the same for purposes of the invention.

From the foregoing data it can be seen that the heatsealed" material has a thickness of approximately one-third of the original nonheat-sealed material. Also, it is seen that the "nonheat-sealed material holds about twice the amount of asphalt as does the heat-sealed material.

The compressibility of the nonheat-sealed" material is considerably greater than the compressibility of the heatsealed" material. lndeed, the heat-sealed material has very little give when pressed between the thumb and forefinger while the nonheat-sealed" material has considerable give. Also, the nonheat-sealed material appears to be compressed in this manner to one-half to one-third its original thickness.

A particularly good surfacing for bridge decks is obtained by use of the invention. Heat-sealed nonwoven polypropylene fabric is made using the following steps: l filaments are randomized on a continuously moving conveyor which also carries a scrim of rayon, cotton, or polypropylene; (2) filaments plus scrim are passed through a revolving spindle of needles so that part of the filaments are punched through the scrim and other randomized fibers, thus forming a nonwoven fabric structure; (3) the fabric is then run through heated rollers (approximately 300 F. for polypropylene) to fuse the filaments or fibers both on the top and bottom surfaces; and (4) the completed fabric is then wound on spools to form rolls about 300 feet in length.

Nonheat-sealed nonwoven polypropylene fabric is made using the above steps, but omitting step (3). This nonheatsealed polypropylene fabric is the nonwoven fabric to which this invention is applied.

Other materials, besides polypropylene, which can be used in making this nonwoven fabric include such a polyvinylchloride and nylon, or the like.

The asphalts which can be used as sealants include the commercially available asphalt cements (penetration grades 40-50, 60-70, -100, l20-l50, and 200-300); the commer- 1 cially available cutbacks (various grades of rapid curing,[RC], medium curing [MC], and slow curing [SC] liquid asphalts or road oils); and the commercially available asphalt emulsions, anionics, cationics, and nonionics.

A particularly useful asphaltic material used in this invention has been a cationic asphalt emulsion, rapid setting grade CRS-l which (ASTM and AASHO tests) has a furol viscosity at 122 F. of 20 to seconds; settlement, 5 days, percent difference 5-; sieve test (retained on No. 20), percent 0. 10 particle charge test of positive; distillation: residue, percent by weight 60+; oil distillate, percent by volume of emulsion 3; and, on the residue from distillation: penetration, 77 F., 100 gms., 5 sec. of 100 to 250; solubility in CCL percent of 97+; and ductility at 77 F cm. of 40+.

Reasonable variation and modification are possible within the scope of the foregoing disclosure and the appended claims to the invention the essence of which is that nonheat-sealed, nonwoven polypropylene fabric or mat has been used together with adhesive and aggregate to form a surface covering as herein described.

We claim:

1. A surface covering suitable for covering roads surfaces, roofs, bridge decks, and the like which comprises an asphalt adhesive, a nonheat-sealed nonwoven polypropylene mat and aggregate laid thereon and smoothed into said fabric and adhesive wherein adhesive completely permeates and impregnates the entire mat and is present in sufficient quantity on top of the mat to receive the aggregate.

2. A method of laying a covering upon a surface which comprises applying an asphalt adhesive coating to said surface, the adhesive coating material when applied being in the fluid state sufiicient to penetrate a mat, laying a nonwoven, nonheatsealed polypropylene mat on said adhesive coating, spreading upon the thus prepared surface layer of aggregate and then compacting said aggregate into said thus prepared surface, the adhesive being applied in a quantity sufficient to be present on top of the mat to receive a compacted aggregate.

3. A method according to claim 2 wherein the composite of the claim is applied to a bridge surface or deck.

4. A method according to claim 2 wherein there is deposited upon the polypropylene mat which has been laid on said adhesive coating a further quantity of adhesive which permeates into said mat and there is then spread upon the thus prepared surface layer of aggregate which is then compacted into the adhesive coated mat. 

1. A surface covering suitable for covering road surfaces, roofs, bridge decks, and the like which comprises an asphalt adhesive, a nonheat-sealed nonwoven polypropylene mat and aggregate laid thereon and smoothed into said fabric and adhesive wherein adhesive completely permeates and impregnates the entire mat and is present in sufficient quantity on top of the mat to receive the aggregate.
 2. A method of laying a covering upon a surface which comprises applying an asphalt adhesive coating to said surface, the adhesive coating material when applied being in the fluid state sufficient to penetrate a mat, laying a nonwoven, nonheat-sealed polypropylene mat on said adhesive coating, spreading upon the thus prepared surface a layer of aggregate and then compacting said aggregate into said thus prepared surface, the adhesive being applied in a quantity sufficient to be present on top of the mat to receive a compacted aggregate.
 3. A method according to claim 2 wherein the composite of the claim is applied to a bridge surface or deck.
 4. A method according to claim 2 wherein there is deposited upon the polypropylene mat which has been laid on said adhesive coating a further quantity of adhesive which further quantity of adhesive permeates into said mat and there is then spread upon the thus prepared surface a layer of aggregate which is then compacted into the adhesive coated mat. 